Alipay Office Towers by WSP in Hangzhou, Zhejiang Province, China

The office towers are set back from the street to create a generous public realm

After a period of copying Western models, China is now developing its own high-rise approaches more rooted in place and culture

Westerners tend to argue that high-rise buildings are emblematic of pollution and uncontrolled development. But a Chinese city has to accommodate a population comparable to that of one or more entire European countries. Ordinary Chinese people are used to life in city centres and the benefits that it affords in terms of convenience, employment and improved public facilities. Under the circumstances, to suggest that people should live close-to-nature in low-rise buildings could be considered ethically wrong.

Like a sponge, China is sucking up nourishment from the West. But what you get when the sponge is squeezed is totally different from the material absorbed. China is creating its own patterns, many of which the West has never experienced. And, of course, in China this process is bound to involve a great deal of cultural, critical, self-reflection.

The Western model of the office tower has transformed over time, from a simple modern box. Think of Tati’s movie Playtime, Mies van der Rohe’s Seagram Building or SOM’s Lever Building through to the figurative expression of Johnson’s AT&T (Sony) Building, Michael Graves’ Portland Building to the recent development of OMA’s diagrammatic CCTV Tower and towers designed with computer technology such as MAD’s Absolute Tower in Mississauga, Canada. Today, in contemporary China, there is a preference for a rational pragmatism while choosing typologies from this office tower genealogy.

As an example, WSP’s Hangzhou Alipay building gives some indication of the potential richness of high-rise building in China. There is a process of emergence with the building’s appearance changing depending on your distance from it. From afar, the blurred twin towers are indistinguishable from the hazy sky. At one or two blocks away, the two rectangular boxes reveal their vivid organisation of glazing with different transparency and frosted glass patterns. Nearer still, and the overall simplicity of the facades and their relationship with the urban environment gives way to a rich play of material, light and shadow.

The changing play of light and shade is enhanced by screens and water features

In China today, the need for privacy is difficult to negotiate. The reality of public desires means that, in fact, gated communities are an economic necessity that competes with the social need for public spaces. The Alipay building is a private development that confronts a similar set of issues.

To resolve this, WSP has developed a layered form that addresses the tension between public and private spaces. The main buildings are set back 30 metres from the street to create the first layer of an urban form: one that provides public urban access as well as an interface to the architecture. The second layer of public engagement is defined by the two slab towers and the podium to form an L-shaped enclosure that denotes a clear but porous boundary between the public and private. The next layer is introduced by the openings along the podium that become controlled access points to the public spaces of the inner sunken courtyard.

The design of the courtyard skilfully introduces the concept of a classical Chinese garden while the landscape remains modern and abstract. Regular repetitions of square green platforms at different heights define a calm but vivid internal public space shared by the employees as well as visitors. The final layer of public engagement is within the towers. Here, semi-public space maximises gatherings and fosters a communal culture.

The overall mass of the building is divided into two blocks according to functional requirements, and these are integrated with each other by the connecting podium. The 8.4-metre structural grid − with cantilevers on all four sides − creates two 21-metre-wide slab towers, each with high efficiency and lower energy consumption. The highly standardised module system helped to speed up the construction and reduce costs, while also achieving visual simplicity and unity.

A double-skin system has been used and the outer glazed skin of the facade has 110-millimetre-wide vertical seams that allow air to flow into the cavity between two layers of glass. This creates a thermal buffer that reduces building energy consumption, while also providing a natural ventilation path. This is a building with a carefully regulated micro-climate.

The double glass skin creates a critical depth that would otherwise be just a superficial pattern. Three types of glazing with different transparency are introduced into the double skin. A layer of white imprinted glazing with open slits serves as a sun-and-wind screen, while the inner layer is a standard full-height window construction. Tenants can operate the windows without disturbing the visual order of the facade. The strategic mix of the three types of glass, together with the grid pattern on the ground of the inner courtyard, conveys a sense of digital visibility − like pixellation − reflecting contemporary digital culture.

The view from inside the curtain wall not only improves the internal environment but also creates lively external visual effects. The multiple patterns of the glazing system allow for different penetrations of light, creating multiple readings of the facade with transparencies, translucencies and shadows that change throughout the day.

In the 12th and 13th centuries, Hangzhou was imperial capital of the Southern Song dynasty, renowned for the pursuit of a comfortable lifestyle. Many people today still consider Hangzhou a city of cultural refinement. Similar to the Chinese appreciation of jade, the reception of such refinement and sophistication extends from the characteristics of translucency, softness and warmness that transcend its exterior hardness − the Alipay building was designed with these associations in mind.

If the quality of high-rise office towers comprehensively reflects economy, social needs, aesthetics and technology, then the Alipay building in Hangzhou is a revealing example of the current condition of architectural design and construction in China. After a wave of cheap copies of Western models in a variety of fields such as electronics, art and architecture, there is now an emerging trend of Chinese architects trying to incorporate a wider range of aspects of design and building quality. Critical pragmatism, sustainable performance, social impact and public engagement, aesthetics and the reflection of local context are all being explored to create architecture with a contemporary Chinese identity.